rtc: isl1208: Update correct procedure for clearing alarm

rtc: isl1208: Update correct procedure for clearing alarm

As per the latest HW manual[1], there is an internal delay(~250 microsec)
from setting ALME = 0 to disabling the alarm function, so the user must
add a short delay of greater than 250µs between setting ALME = 0 and
clearing ALM.

Currently setting of ALME = 0 is done after clearing the ALM, so just
reverse the operation and add a delay of 275 microsec.

[1]https://www.renesas.com/us/en/document/dst/raa215300-datasheet?r=1506351

Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Link: https://lore.kernel.org/r/20240618152635.48956-3-biju.das.jz@bp.renesas.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>